A known device, described inter alia in European application no. 88830477.1 (no. 0317.523), is capable of forming a yarn constituted by a linear manufactured article made of tying yarn, in particular a tubular knitted manufactured article, with opened fibers which are anchored to the stitches and project at least partly externally in order to impart a raising effect to the composite yarn thus formed.
The device for producing the yarn comprises at least one means of feeding a corresponding roving or top of fibers to be opened, at least one rotating card member, to which the roving is fed, which card member separates the fibers of the roving, means forming a cavity for conveying the opened fibers, a typing chamber with yarn-guide passages for the penetration into it of typing yarns, and means of working the tying yarns in order to form with these a filiform manufactured article engaging the opened fibers fed to the tying chamber. These means for working of the tying yarns comprise--in one of the embodiments described--a knitting machine capable of forming an essentially filiform tubular manufactured article. The working zone of the needles is inside the tying chamber. The knitting machine is circular, has a limited number of needles and is of the type forming thin tubular manufactured articles using one or more feeders and using a continuously rotating device which carries the needles or the means for control of the needles.